All Questions

-1
votes
0answers
6 views

Is it correct to apply the vis-viva equation when there are two forces acting on the orbiting body?

The vis-viva equation models the motion of an orbiting body and it applies when the only force acting on the body is it's own weight. So is it correct to apply this equation to an airplane that flies ...
5
votes
1answer
405 views

How best to maneuver inside a large room within a space station using only arm and leg motion?

Imagine the following thought experiment: An astronaut is inside an extremely large room within a space station. Suppose that she, for whatever reason, is initially at a zero velocity with respect ...
1
vote
0answers
17 views

JPL ephermeris table

For an interplanetary mission design problem, I am using the JPL New Horizons Ephermeris to obtain the state vectors of Venus and Earth. I have selected the Coordinate origin as the body centre of the ...
2
votes
1answer
34 views

Chang'e 4, what is planned during December 12 and January 3?

Chang'e 4 is in Moon orbit since December 12, the landing is scheduled for January 3. What is planned during the 22 days in orbit?
0
votes
0answers
50 views

Parasite Satellite

With computers and technology becoming lighter and is also effected by drag. Could a small satellite that lacks certain systems be designed to utilize an existing satellites systems like radio, solar ...
1
vote
0answers
38 views

Are 2 satellites joined better than 2 apart?

Could smaller satellites be designed to intercept other functioning artificial satellites or space junk already in orbit to add weight to the small satellite in order to last longer in orbit?
3
votes
1answer
52 views

Is it safe to consume food that's been exposed to cosmic rays?

Related to this question: Could the void of space act as a good refrigerator for food in long journeys? I don't have enough rep to comment and don't have the answer to this question but it feels to ...
1
vote
1answer
40 views

Would a debris field on Mars look like one on either the Earth or the Moon?

I am assuming there are no photographs, with enough resolution, of the any of the debris fields of Mars probes that crashed into the surface of Mars to indicate what the debris field looks like. I am ...
1
vote
0answers
18 views

What is the Cheapest way to track my balloon (only altitude or gps coordinates)? [on hold]

I want to build extreme cheap high altitude stuff - balloon, paper plane :) anything. Its cold outside now, and i dont want to track, and collect the my landed "spacecraft". So, i need a very cheap ...
0
votes
2answers
166 views

Is there any record of planetary movement, relative to us?

I was discussing with some friends in addressing every possibilities of geocentric model of universe using experimental evidence rather than eyesight. But then one guy (in geocentricist-side) asked, ...
1
vote
1answer
46 views

Is it correct to apply the vis-viva equation to an airplane that flies in a straight line at the Kármán line?

The vis-viva equation models the motion of an orbiting body and it applies when the only force acting on the body is it's own weight. So is it correct to apply this equation to an airplane that ...
2
votes
1answer
57 views

What causes those curtain-like hot and cool spots in the 2nd stage nozzle of this Electron ELaNa 19 launch?

Here is a GIF that I made of the recent Electron Launch from frame grabs in the Rocket Lab video ELaNa 19 Launch - 12/16/2018 It is about 4M, so it won't fit in SE's normal image import. Frames are ...
3
votes
0answers
29 views

How do NASA Venture Class Launch Services Contracts work?

The Rocket Lab YouTube video ELaNa 19 Launch - 12/16/2018 contained a short video which was preceded by the following explanation after about 08:00: Today’s ...
-2
votes
0answers
72 views

Complete Solar System in one “photograph” [on hold]

Our satellites have recently traveled just beyond the solar system. We have not even crossed one arm of our galaxy, and still humans hold various perceptions about other galaxies, the clusters, super ...
3
votes
0answers
83 views

Why are lightning towers at launch pads topped with big hollow tubes with spiral windings and not “lightning rod-shaped” lightning rods?

Why are the lightning towers around launch pads topped with big hollow tubes with spiral windings? Why not conventional lightning rods - big metal rods with pointy things at the top? Possibly ...
2
votes
1answer
34 views

Map image (x,y) to spherical coordinates [on hold]

What is an efficient method to map image pixels (2D-Cartesian) to their spherical coordinates given camera azimuth and elevation? (Ideally, response includes mathematical notation/Python/C++)
-2
votes
1answer
99 views

What is the origin of Black knight satellite? [on hold]

Is it true that an extraterrestrial satellite orbits earth in retrograde? If the Black knight exists, can we presume that it is placed there by aliens who are technologically more advanced than ...
0
votes
1answer
83 views

Artificial ring around the Earth?

What pros and cons would a orbiting ring have for Earth? Is there enough satellites in orbit to form a joined ring?
5
votes
0answers
36 views

What are the practical uses of a state transition matrix?

I am studying different dynamical models of relative motion of satellites. In my work, I've always just used a numerical integrator like RK78 to integrate the cartesian system of equations: $\dot{r}=...
5
votes
2answers
109 views

Does prolonged space flight have any effect on the physical traits of the human body?

Can a variable of physical traits like height, weight, complexion be changed in outer space? Maybe by gravity or by something else that determines these traits (like the UV rays of the sun that ...
0
votes
1answer
40 views

What kind of ground-based radio astronomy is NASA's DSN used for? Who are the PIs?

I looked at DNS Now to check on Hayabusa-2 and compare to http://haya2now.jp/en.html and saw that DSS 34 in Canberra is currently in setup/teardown for Ground Based Radio Astronomy! In this status ...
1
vote
1answer
105 views

Could it be worthwhile to bring a small and simple greenhouse with biofilms along with one of the next missions to Mars?

Planetary protection rules could be a reason not to bring biofilms to Mars, but because several landers and satellites that crashed or landed on Mars were probably not sterilized these rules were ...
6
votes
2answers
1k views

How many engines are restarted for landing the falcon boosters

For landing the boosters, it is clear that SpaceX is using the center engine, but I suspect that igniting one engine will not be helpful. If they aren't igniting all the 9 engines, how are they ...
0
votes
0answers
57 views

Can Mars provide vitamins?

How long can nutrients found in Mars along with an algae diet sustain human life?
5
votes
1answer
159 views

Is there really moon rock in this cathedral window? If so, how, and from where on the Moon?

This Tweet by NASA Space Flight Editor Ian Atkinson says: Some pictures from the Cathedral before the event starts, they have a table set up with artifacts from Apollo 8, including the flown ...
0
votes
0answers
47 views

How does the camera make the exhaust of the Electron's RP-1/LOX exhaust transparent?

In this 20-Nov-2018 Tweet from Rocket Labs XXX Peter Beck there is an image of the nine Rutherford engines of an Electron rocket burning. What is unusual is that the exhaust is luminescent but at the ...
2
votes
1answer
99 views

Pressurized Organic Oxygen Pods

Human waste could be used in a hydroponics facility to grow algae in space or Mars in pressurized tanks, and the photosynthesis can be used to convert CO2 to breathable oxygen. A carbon dioxide ...
2
votes
2answers
52 views

Calculating thrust pressure from ion thruster for rocket thrust equation

So recently i have been very interested in the possibilities of using ion thrusters as power interstellar propulsion units, however when it comes to calculating ISP it have absolutely zero idea how ...
2
votes
0answers
47 views

What is the largest antenna deployed in space?

@Tristan's answer says: The satellites are classified, so details are speculative, but it is believed that the Magnum/Orion and Mentor SIGINT satellites have parabolic antennae around 100 m in ...
0
votes
0answers
21 views

What is InSight's one-sol energy budget like on a good day?

I am worried about InSight's solar panels getting covered in dust: Why do InSight's solar panels have tall vertical ridges between segments - will these trap dust? Help me to sleep better. What would ...
0
votes
0answers
21 views

From where do all the space agencies receive signals from scientific spacecraft from launch to deep space?

The ISRO web page Ground Segment says: SRO Telemetry Tracking and Command Network (ISTRAC) will be providing support of the TTC ground stations, communications network between ground stations and ...
4
votes
1answer
96 views

Mass manufacturing of satellites

Airbus has announced a mass-manufacturing unit for OneWeb constellation of satellites. See for example Space News' With a new satellite factory in the U.S., Airbus eyes opportunities in military space ...
45
votes
5answers
14k views

Has alcohol ever been consumed in space?

Conversation at the bar led to space travel, and whether each of us would commit to the journey to Mars. It came up that instead of going to the bar, you would need to brew your own beer. This led to ...
0
votes
0answers
15 views

Are Hayabusa-2's high gain antenna disks electrically point-able?

Writing this answer I realized that Hayabusa-2 has two very similar looking circular flat disks that serve as it's high gain antennas. One is dedicated to X-band (7-8 GHz) and the other to Ka-band (32 ...
4
votes
2answers
80 views

What are some notable cold gas thruster propellants, and why?

Cold gas thrusters are a very simple and reliable form of thruster that operate only by spraying a compressed gas, without any chemical reaction. What are the most common, performant, or otherwise ...
6
votes
1answer
73 views

What would the human gait look like on Mars?

Is there an approximation of what a human would look like walking on Mars? Would it be closer to how the astronauts walked on the moon or the way we walk on the Earth? With the gravitational ...
2
votes
2answers
55 views

How does Hayabusa-2's “Communication Simulator” on its website work? What does it show?

The pinned tweet on Hayabusa-2's Twitter account leads to http://haya2now.jp/en.html which is a kind of control panel readout of the spacecraft's situation. I clicked ...
0
votes
1answer
30 views

Diagram of Hayabusa 2 in “Hill Coordinate System”; what is that exactly? How to convert it to inertial?

These JAXA's Hayabusa-2's two Tweets: 1 2 show a diagram of the spacecraft's motion relative to Ruygu in what they call a Hill Coordinate System, This is a diagram of the trajectory during solar ...
24
votes
4answers
306 views

Why doesn't NASA send Voyagers anymore?

It's been more than 40 years since NASA launched Voyager 1 & Voyager 2. With more advanced technology, wouldn't it now be a good time to continue sending more sophisticated Voyagers out there? ...
2
votes
0answers
56 views

What was the nature of the visible part of the viscous wake trailing the Apollo CM during reentry?

This diagram suggests a helix in the wake, was it a single-helix, a multiple helix, or a superhelix? Is there any other part of the wake that would be visible?
4
votes
0answers
39 views

What determined the closest-approach distance between New Horizons and Pluto? [duplicate]

New Horizons passed 7,750 mi (12,472 km) from the surface of Pluto at its closest approach, limiting the image resolution to about 600 feet (183 m). What set the specific closest-approach distance? ...
2
votes
2answers
36 views

Examples of gamma ray or X-ray imaging of small planets, moons, or asteroids, or at least how to calculate intensity thereof?

Have any spatially resolved measurements of gamma rays or X-rays from medium and small solar system bodies been collected from space? These might be planets, moons, or asteroids for example, but ...
3
votes
0answers
53 views

Orion reentry plasma

Below are two screen shots from the video of the Orion reentry, Astronaut’s-Eye View of NASA’s Orion Spacecraft Re-entry, and a diagram. Is the plasma contained, or primarily within the viscous wake, ...
14
votes
1answer
2k views

Did the Apollo astronauts ever describe reentry deceleration?

Did the Apollo astronauts describe any differences in how it felt in the CM as it passed between the hypersonic, supersonic, transonic and the subsonic zone? Did the CM shake more or less in ...
5
votes
1answer
106 views

How would humans with appropriate equipment travel the surface of Saturn's moon Titan on foot?

Taking into account the physical characteristics of Titan (e.g. surface gravity, atmospheric pressure), what would be the most efficient method of motion for an astronaut to travel the surface of ...
1
vote
0answers
20 views

Quantitative plots of v, T, p, vs position from chamber through nozzle to ambient for a few canonical modern engines?

In this answer I showed the schematic diagram of a basic de Laval nozzle and representative plots of how temperature, pressure and and velocity would behave. It can be used as a rough representation ...
0
votes
1answer
58 views

Perpetual motion [on hold]

When I was young, I had a set of bar magnets which had poles on the side faces (across the thickness) and not at the two ends. I placed one on the table facing one pole upwards (say north pole). ...
5
votes
1answer
132 views

If Oumuamua was alien space-junk, what would it look like, and would we be able tell?

I'm interested in our recent interstellar visitor 'Oumuamua. Whilst I'm happy to accept the official explanation of what it is, I'm curious about what state it would be in if it was actually alien ...
3
votes
1answer
65 views

How will the Parker Solar Probe's data transmission keep up with data gathering?

The NASA article Preparing for Discovery With NASA's Parker Solar Probe says that we are now receiving data from the probe's first pass, but also that we will not receive all of the first pass's data ...
4
votes
1answer
93 views

How much delta-v is lost to heat of exhaust?

It occurred to me that all of the kinetic energy not going exactly in the opposite direction of a spacecraft is wasted! Since heat is essentially kinetic "noise" in objects, I wondered how much more ...

15 30 50 per page